The invention relates to product delivery control and, more particularly, to securing product storage tanks against unauthorized delivery.
Retail facilities selling liquid products stored in liquid storage tanks (e.g., gas stations) are located throughout the world. In the case of petroleum, products are stored in bulk storage tanks, which are typically located underground. Each tank stores a unique petroleum product (e.g., gasoline, diesel, kerosene, etc.) to be dispensed through pump-dispensers at various retail facilities. The delivery of petroleum products (hereinafter, fuel) to retail facilities is conducted by a gravity drop from a compartment in a tanker truck. These tanker trucks are themselves loaded for delivery from larger tank systems located at wholesale distribution centers.
Preventing unauthorized fuel delivery is desirable for automotive fuel brands to maintain their brand products' exclusivity in the franchise retail gas stations, for fuel distributors in order to fulfill their exclusive relationships with retail gas stations, and to prevent contamination or improper mixing of fuel products. A business goal of fuel distributors is to minimize unauthorized deliveries while maximizing the efficiency of authorized delivery operations. Unauthorized deliveries may take place at a time of fuel price fluctuations. When prices go down, the owner of a retail gas station might be tempted to purchase fuel from a freelance distributer at a lower price, breaching the long-term supply contract with a distributor.
Typically, distributors keep close track of their customers' inventory, but in practice, even with well monitored retail gas stations, distributors report that unauthorized deliveries cause them a loss of 2-20% of their total business. That is a loss of between $1.75 million and $17.5 million PER DAY for authorized distributors in the United States during the first six months of 2011 (calculation based on data from the Prime Supplier Report and the U.S. Energy Information Administration, which report that in the first half of 2011, total gasoline sales and deliveries was approximately 350 million gallons per day with an average distributor's margin of $0.25 per gallon).
Current methods for preventing unauthorized delivery of liquid cargo into a storage tank includes the collection and comparison of point-in-time storage tank levels, storage volume history and delivery records for a retail station. If a deviation is found, the dealer representative works with the retail station manager to investigate and correct the situation. This method fails to prevent unauthorized delivery because (a) it is post factum and, under the circumstances, it is difficult to prove wrongdoing, (b) an investigation typically has a negative effect on the distributor-customer relationship, (c) it is costly, and (d) it doesn't provide a means to prevent product-type contamination due to human error.
Remote controlled valves have been previously used in other industries (e.g., water irrigation system), but have not been suitable for fuel or other industrial liquid products because (a) they do not support bulk liquid drops at very low hydrostatic pressure, (b) they are not effective for bidirectional flow, (c) they are hard to use in a flammable explosive environment, (d) they are not suited for battery operation due to energy consumption, and (e) they are typically unreliable, expensive, and difficult to use. The RCVs used herein are suitable for allowing rapid bulk-liquid drops at any hydrostatic pressure, supporting bidirectional liquid flow and handling flammable liquids securely, including supporting ongoing maintenance, inspection and auditing activities without compromising on safety or security.